The present invention relates to a wiper arm for a vehicle.
More particularly, it relates to a wiper arm which includes an arm part and a mounting part which are connected articulately by a hinge with one another, so that a relative turning movement of the arm part and the mounting part is limited by an abutment.
Wiper arms for vehicles are known, whose mounting on the vehicle is complicated, since additional mounting auxiliary means are needed for correct mounting, to hold the wiper arm in a predetermined mounting position. This mounting auxiliary means must be removed after the mounting of the wiper arm on the vehicle, since they are not needed for a correct operation of the wiper arm, but instead represents an obstacle. Furthermore, this is disadvantageous since it is possible that the mounting auxiliary means which are not correctly mounted and operate for mounting can cause delayed or undesired damages to the wiper arm and/or vehicle (vehicle window) by mounting auxiliary part which is unexpectedly lost from the wiper arm. After the mounting and fixing the mounting auxiliary means, the arm part of the wiper arm is turnable from an operational position into a turned down position, in which the arm part projects approximately perpendicularly outwardly from the vehicle and in particular from a vehicle window.
Accordingly, it is an object of present invention to provide a wiper arm which avoids the disadvantages of the prior art.
In keeping with these objects and with others which will become apparent hereinafter, one feature of present invention resides, briefly stated, in a wiper arm for a vehicle, in which the abutment means is composed of two abutments which are spaced from one another and an abutment element, which is bringable into an operative contact with the abutments upon a corresponding turning movement of the arm part and/or the mounting part, wherein the abutment is formed of one piece with one of the parts, while the abutment element is formed of one piece with the other part.
Because of the one-piece structure of the two abutments and the abutment element of the corresponding part (arm part, mounting part) of the wiper arm, it is prevented that for positioning of the wiper arm in a stable mounting position. Additional, releasable mounting auxiliary means must be used which are removable after the mounting of the wiper arm on the vehicle. Thereby a simple, fast and reliable mounting of the wiper arm on a vehicle is guaranteed.
Due to the presence of the two spaced abutments, it is further possible to fix a definite turning region of the arm part relative to the mounting part of the wiper arm from a mounting position to a turned down position. Thereby both the mounting position and also the turned down position of the arm part, because of the operational contact of the abutment element with the corresponding abutment, represent a stable end position of the turnable arm part of the wiper arm. With the thusly fixed turning limits of the wiper arm, a correct mounting of the wiper arm (mounting position) and a reliable wiper blade exchange (turned down position) on the vehicle are possible. A mounting of a mounting auxiliary means (additional part) after the wiper arm manufacture and a dismounting of the mounting auxiliary means after the wiper arm mounting on the vehicle are dispensed with. It is also advantageous to provide two turning limits in two opposite turning directions of the arm part with a single abutment element.
In accordance with an advantageous embodiment of the invention, the abutment means is arranged inside a hinge overlapping region of the hinge means. For this purpose, on the one hand a compact construction of the hinge means is provided, and on the other hand, an outwardly actuatable and/or visible geometric design of the hinge means is possible.
In accordance with another advantageous embodiment of the present invention, the turning movement of the arm part and/or mounting part between a mounting position and a turned down position of the wiper arm is performed. For this purpose the mounting position serves a simple and correct mounting of the wiper arm on the vehicle, while the turned down position represents a wiper blade exchange position of the wiper arm. The arm part of the wiper arm is thereby turnable from a defined, stable mounting position against an elastic restoring force (for example of a spring element formed as a pulling spring between the arm part and the mounting part) to a defined, stable turned down position and again back to the mounting position.
An equilibrium position of the wiper arm is advantageously located between the mounting position and the turned down position. In the equilibrium position, an instable position of the arm part relative to the mounting part takes place. The arm part in the equilibrium position is loaded with an elastic restoring force of a spring element provided in the hinge means (pulling spring). Since the turned down position during turning of the arm part from the mounting position is located behind the equilibrium position of the wiper arm as considered from the mounting position, the restoring force of the spring element acts in the turned down position, in which the abutment element is in operative contact with the corresponding abutment, and also in the mounting position acts stabilizingly on the arm part.
In accordance with another advantageous feature of the present invention, the operational position of the wiper arm is located between the mounting position and the equilibrium position. Since in the mounting position the abutment element is in the operative contact with the corresponding abutment, it is advantageous that the operative position of the arm part is spaced from the mounting position, so that the wiper arm in the operative position can turn in two opposite turning directions during the operation which are perpendicular to the vehicle window. Thereby the wiper blade arranged intermediately abuts under action of an optionally adjustable pressing force of the spring element (pulling spring) reliably on the window surface of the vehicle, independently from the corresponding contour of the window surface.
In accordance with a preferable embodiment, the abutment element is formed on the arm part which is arranged in the hinge overlapping region outwardly with respect to the mounting part. Since the abutment element is formed on the arm part which simultaneously acts as an outer hinge part, it is possible to no longer influence the abutment means from outside and make it completely invisible. This also provides a protection of the abutment part from outer, negatively acting influences, such as for example dirtying and/or damaging of the contact surfaces of the abutment, or the abutment element. It also makes possible an outwardly homogenous and compact design of the hinge overlapping region. Furthermore, with the inwardly located abutment means, the injury danger for example by clamping a fingers between the abutment element and the abutment is substantially reduced.
In accordance with a further embodiment, the abutment element is mounted on the mounting part, which is arranged in the hinge overlapping region outwardly relative to the arm part. In this embodiment, there is an inwardly located abutment part with the above mentioned advantages.
Advantageously, the embodiment means is formed of one piece on the hinge means. With a one-piece construction of the abutment means on the hinge means, the mounting cost for producing the wiper arm are reduced. It is advantageous that the abutment means is arranged on the hinge means at the side which is opposite to the vehicle interior space.
Preferably the abutment means is formed on both sides on the hinge means. By the two-sided construction of the abutment means on the hinge means, a force-symmetrical hinge holding of the arm part on the mounting part is possible. The two abutments which act in the mounting position and in the turned down position at both sides and the abutment element arranged at both sides, provide an additional securing with regard to a correct and precise positioning of the arm part relative to the mounting part.
Advantageously, the abutment element during abutment is formed as a projection which is loaded with bending and extends in the hinge overlapping region into the interior of the wiper arm. With such an abutment element which is loaded for bending, the operative contact between the abutment element and the abutment is obtained by a friction contact of two preferably plane surfaces which come in a flat contact with one another and slide over one another. Thereby the arm part with respect to the mounting part is slightly braked before reaching its corresponding stable end position, by a friction force acting against the corresponding turning direction.
Preferably such an abutment which causes on the abutment element a bending is provided for the mounting position, so that the arm part can automatically turn back from the unstable equilibrium position at high speed to the mounting position, because of the acting relatively high elastic restoring force of the spring element which acts as a pulling spring.
The abutment element for the abutment is advantageously formed as a projection which is loaded with sheering and extends in the hinge overlapping region in the interior of the wiper arm. The abutment element which is loaded with sheering is in operative contact with an end-side surface as seen in the movement direction, with a corresponding abutment. Therefore in this case, there is not only a defined limiting of the turning path such as the turning angle of the arm part by a force-transmitting connection between the abutment element and the abutment, but also a geometrical limiting (frontal abutment) of the turning path, such as the turning angle.
Advantageously, a curvilinear recess is provided between the two abutments. Thereby the construction of a compact and simultaneously robust abutment means is possible, since the curvilinear recess can be adapted to the turning path of the abutment element.
In accordance with a further embodiment, a rectilinear recess is provided between the two abutments. By a suitably formed rectilinear recess, advantageously a material saving in the hinge region and a corresponding weight reduction of the wiper arm is obtained with a guarantee of an average stability.
In accordance with a preferable embodiment the abutment element has a flat abutment surface. With a flat abutment surface of the abutment element, and a correspondingly formed abutment, the pressure or friction forces produced during the operative contact acts advantageously in a relatively great surface region. Thereby the possibility of a not desired plastic deformation of the elements, which are in operative contact in condition of high abutment forces, is reduced.
In accordance with a further embodiment, the abutment element has a curved abutment surface. With a curve, for example cylindrical abutment surface of the abutment element and a flat contact surface of the abutment, the effectively acting abutment surface of the abutment element and the abutment is relatively small. Hereby a cylindrical abutment surface of the abutment element is especially advantageous, since because of the rotation-symmetrical construction of the abutment surface, no special angular adjustments of the arm part relative to the mounting part for producing a correct operative contact between the abutment element and the abutment must be taken into consideration.